This is certainly thinking outside the box, a compressed air hybrid! Let’s hope it becomes feasible and popular. It would make a great city car.

PSA Peugeot Citroen is working on a drivetrain that would hybridize a conventional engine with compressed air in one of the automaker’s B-segment compact hatchbacks. The vehicle, which could go into production as soon as 2016, would include a hydraulic pump that allows the car to run in all-gasoline, all-air or combined (aka “hybrid air”) modes.